It will be but a single Sayhah, so behold they will all be brought up before Us!
This is like the Ayat:
فَإِنَّمَا هِىَ زَجْرَةٌ وَحِدَةٌ
فَإِذَا هُم بِالسَّاهِرَةِ
But it will be only a single Zajrah, when behold, they find themselves (on the surface of the earth) alive (after their death). (79:13-14)
وَمَأ أَمْرُ السَّاعَةِ إِلاَّ كَلَمْحِ الْبَصَرِ أَوْ هُوَ أَقْرَبُ
And the matter of the Hour is not but as a twinkling of the eye, or even nearer. (16:77)
and,
يَوْمَ يَدْعُوكُمْ فَتَسْتَجِيبُونَ بِحَمْدِهِ وَتَظُنُّونَ إِن لَّبِثْتُمْ إِلاَّ قَلِيلً
On the Day when He will call you, and you will answer (His call) with (words of) His praise and obedience, and you will think that you have stayed (in this world) but a little while! (17:52)
which means, `We will issue but one command, and all of them will be gathered together.'